Sample Introduction Device Purge Gas Channel Carryover Prevention
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Solution Overview
Problem
In head-space type sample introduction devices, components of the gas derived from the head space can remain in channels and be adsorbed, leading to potential carryover and decreased analysis accuracy, especially in low-concentration samples or blank analyses.
Innovation Solution
A sample introduction device is designed with an additional channel that supplies gas to the channel between the collection unit and the discharge valve during the derivation state, preventing components from diffusing to the collection unit side.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If gas is supplied into the sample container to pressurize the head space, then the vaporized component can be derived to the outside, but components in the gas may remain in the channel and be adsorbed, leading to carryover
Solution Approach 1:
A purge gas flow is introduced as an intermediary substance to interact with and displace the sample gas in the channel. The purge gas flows from the discharge pipe side toward the collection unit side, carrying adsorbed components out of the channel and preventing them from diffusing back into the collection unit during the derivation process
2Speed
If the pressure of the gas derived from the head space is high, then the vaporized component can be efficiently discharged, but components remaining in the channel are less likely to diffuse to the collection unit side
Solution Approach 1:
The purge gas flow is activated in advance during the derivation process to preemptively prevent component diffusion. By establishing a counter-flow of purge gas before components can diffuse back into the collection unit, the system proactively eliminates the carryover risk rather than reacting to it after it occurs
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This configuration effectively prevents components remaining in the channel from diffusing to the collection unit side, thereby maintaining analysis accuracy and preventing carryover of high-concentration sample components during low-concentration or blank analyses.
Implementation Method 1
The additional channel supplies gas to a channel between the collection unit and the discharge valve in the derivation state
Data Source
AI summary
A switching mechanism 110 can perform switching to a pressurized state in which gas is supplied from a pipe 203 to an insertion tube 101, or a derivation state in which gas in a head space 23 that is pressurized is derived from the insertion tube 101 to the pipe 207 via a collection unit 104. The switching mechanism 110 includes a discharge valve 103 that puts the insertion tube 101 and the pipe 207 into a non-communication state in the pressurized state and puts the insertion tube 101 and the pipe 207 into a communication state in the derivation state. A resistance pipe 206 supplies gas to a channel between the collection unit 104 and the discharge valve 103 in the derivation state.